Near-field exposure method

A near-field exposure method wherein an exposure mask having a light blocking film with an opening smaller than a wavelength of light from an exposure light source is used and wherein an object to be exposed is exposed by near-field light produced at the opening of the exposure mask based on the exposure light from the exposure light source, the method comprising:

• a step of determining a width of the opening so as to satisfy equations (1), (2) and (3) below, where the width of the opening of the exposure mask is denoted by s (nm), a processing pitch of the object to be exposed is denoted by p (nm) and coefficients are denoted by a and b,
• s=ap−b (1)
• 0.46≦a≦0.58 (2)
• 3≦b≦13 (3)
• a step of preparing the exposure mask having the opening with the width determined by said determining step in order to obtain a largest intensity gradient of the near-field light at a distance corresponding to ¼ of the processing pitch from the center of the opening;
• and
• a step of projecting the exposure light to the exposure mask to thereby expose the object to be exposed.